How many liters are in a gram?

One litre of water has a mass of almost exactly one kilogram (1000 gram). So, 1 gram is equivalent to 0.001 litre. 1 litre of chemically pure water has a mass of 1 kg at 277.13 K (3.98 °C or 39.164 °F), at which point the pure water occupies the minimum volume per mass.